Heating apparatus



July 6, 1943. s. P. FOLTZ HEATING APPARATUS Filed-Nov. 2, 1940 Patented July 6, 1943 UNITED STATES PATENT OFFICE HEATING APPARATUS Stewart P. Foltz, New Castle, Pa.

Application November 2, 1940, Serial No. 863,987

14 Claims.

This invention relates to low pressure boilers or generators of the Vapor, steam, or hot water type, and more particularly, to water heating apparatus for use in heating homes, buildings and the like, or in heating hot water for commercial or domestic purposes.

Heretofore, various types of hot water and other heating apparatus have been provided. Various assertions have been made in regard to the efiiciency and the cost thereof. However, I have found that substantially all apparatus for heating homes, small or medium sized buildings, and for heating water for domestic purposes or for relatively small commercial installations are relatively expensive in initial cost, troublesome and costly to maintain, or have an undesirably low efiiciency.

It is the general object of my invention to avoid and overcome the foregoing and other difficulties of prior art practices and apparatus by the provision of improved, relatively inexpensive apparatus for rapidly supplying hot fluid, which apparatus is of high emciency, readily installed and operated with unequalled economy, and in which the maintenance costs are negligible.

Another object of my invention is to provide a boiler in which the basic heat transfer unit is made from a pair of pressed steel and copper alloyed plates or sheets which are inexpensive to produce and which have a very long operating life.

Another object of my invention is the provision of a boiler having a plurality of heat transfer units which are mounted in side by side relation to provide a boiler having the desired capacity.

Another object of my invention is the provision of an apparatus for heating water or other liquid and in which it is unnecessary to drain the water, even though there is danger that the water may freeze inside the boiler and expand the sides of the sections.

Another object of my invention is to provide a sectional boiler with no horizontal surfaces which could cause accumulation of ash or soot thereon, said boiler having novel and easy means of access to its inter-sectional spaces for any cleaning which might be necessary.

Another object of my invention is to provide a water heating apparatus in which the maximum flue gas travel surface is used to pre-heat the air employed for combustion purposes.

Another object of my invention is to provide a boiler for domestic or like purposes in which any type of heating means can be efficiently employed.

Another object of my invention is the provision of a contra-flow boiler in which the stream of water to be heated is divided into a plurality of parts and which eventually ends up in its fin'al flow as a direct-flow boiler.

' Another object of my invention is to provide a boiler in which the inlet and outlet conduits are adjacent to each other.

Another object of my invention is to provide a boiler in which the stream of water to be heated is carried in an undulating or circuitous path between two plate members and in which internal leakage of the water is not important or detrimental and which lack of detriment reduces manufacturing cost.

Another object of my invention is to provide a boiler for heating apparatus in which there is a finer division of the hot gases, and the tubes or passages for carrying the water during heating are formed by stamping or pressing of fiat metal plates, and in which there can be no deposit of fly ash or soot, and cleaning is a relatively simple matter.

Another object of my invention is to provide a boiler in which the water to be heated is passed through a passage or conduit of a semi-fiat or oval shape in cross-section and having baflies or fluid stirring means therein so that the result is a much smaller or a negligible cold core of liquid at the center of the passage or conduit.

Another object of my invention is the provision of improved heating apparatus in which expansion and contraction either internal or of the assembly plays no havoc and in which the headers themselves can be made of extruded copper or other material and in a standard commercial form. I

Another object of my invention is to provide a boiler for heating liquid used for heating purposes and incorporating means for heating hot water for domestic consumption.

The foregoing and other objects of my invention are achieved by the provision of a heating apparatus including a boiler, a fire box, means for supplying a flow of hot gases upwardly from the fire box, a casing positioned above the fire box, a plurality of units positioned in side by side but spaced-apart relation in the casing and extending down into the fire box so that the hot gases will pass upwardly between the units, a stack header mounted removably on the top of the casing and adapted to carry the hot gases to a stack, a combustion-air header surrounding the stack header but spaced therefrom and removably mounted on the casing, the air-header being connected to and supplying combustion-air for the means for supplying hot gases, an inlet conduit connected to each unit, and an outlet conduit connected to each unit adjacent to the inlet conduit. Each of the units in the assembly includes a pair of metal plates abutting face to face, the plates being pressed outwardly in juxtaposed areas to form a relatively long undulating passage which is substantially oval in cross section and connected at one end to the inlet conduit and terminating in a substantially vertical passage at one end of the unit, the vertical passage being connected to a plurality of upwardly inclined passages in turn connected to a substantially vertical passage connected to the outlet conduit, each of the units being spot welded together at the smallest practicaFnumber of points between the passages and being seal-welded together around its edges. made first and hold the two plates in juxtaposition during the subsequent seal-welding operation.

For a better understanding of my invention reference should be had to the accompanying drawing, wherein Fig. l is a side elevation of one embodiment of my invention with the greater portion thereof being broken away (on line 1-1 of Fig. 2) so as to show the internal construction; Fig. 2 is a vertical cross-sectional view taken on line IIII of Fig. 1; Fig. 3 is an enlarged cross-sectional view taken on line III-III of Fig. 2 and illustrating the construction of one of the heating units present in the assembly; and Fig. 4 is a longitudinal sectional view taken on line IVIV of Fig. 2.

In the drawing, the numeral l indicates, as a whole, a casing which surrounds the fire box l2 adapted to contain any suitable source of heat. For example, my improved apparatus is adapted to burn equally well either gas, oil, coal, coke or other known fuel, but I have conveniently illustrated an oil burner H1 in association with the fire box l2. The burner I4 is located in an associated casing It usually formed integral with the main casing It with the casing being separated by a wall W The upper part of the casing l0 defines a chamber adapted to receive a plurality of heat transfer units IB. Each unit it includes a pair of metal plates l8 abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a conduit or passage of a substantially oval or almond shape in cross section. The passage 20 near the top of each unit I6 is connected to an inlet header or conduit 22 and is formed in an undulating manner, as at 20 so as to provide a relatively long passage in the cooler gas zone to obtain the best type of heat exchange action. The undulating passage 2m terminates in a substantially vertical passage 20 which extends along one edge of each unit It and the passage Zll is connected to a plurality of upwardly inclined passages 20 which are connected at their upper ends to a second substantially vertical passage 29 which is connected to an outlet header or conduit 24.

It will be seen that water or other liquid introduced into the unit l6 by way of the inlet conduit 22 will flow substantially in the direction indicated by the solid arrows through the passages 28 20*, 28 and 20 and out of the outlet conduit 24. The arrangement of the passages 20 in each unit I6 is such that the best possible type of heat exchange action is obtained between the liquid in the passages and the heat outside the unit.

The spot welds are Also, it will be seen that the arrangement of the passages 20 is such that the heat introduced into the liquid in the passages causes a normal flow of the liquid through the unit by virtue of the upwardly inclined tubes being located in the hottest fire zone. The oval or almond shape of each passage 2! reduces to a minimum any cold liquid core which might be present at the center of the passage and any deposit of fly ash or soot on the outer surface of each unit is substantially prevented by the almost continuously vertical surface of the sections. Preferably I provide a plurality of inwardly extending baffles, ribs, or corrugations 25 in each of the several passages 20 20*, 2'6 and 20 which baffles are usually directed at right angles or substantially right angles to the flow of liquid and which are to agitate and stir the fluid so that it is substantially uniform in temperature throughout its entire cross section. The bafiles 25 are, of course, pressed into the plates l8 during their forming.

Each heating unit of section it is welded in a tight leakproofmanner around its entire periphery, and the plates i8 ofeach unit are spot welded together at a minimum plurality of 'points 26 between the passages 28. Minimum of spotwelding is employed in order to allow expansion of'the 7 sides of the sections to accommodate the formation of ice within the sections. The plates l8 may be just spot welded together between the passages 20 because internal leakage from one passage to another is ordinarily relatively small and is unimportant in the operation of each unit. The shallow pressing of the plates l8 to the shape shown in the drawing is a relatively simple die operation and the pressed plates H! can be quickly and inexpensively produced. Also, the spot welding operation is inexpensive and quickly performed and the welding around the periphery of each unit can ordinarily be done by rollerelectrode, resistance-welding apparatus, and is likewise inexpensive.

I employ any desired number of the units It in side by side relation in the casing I0 in order to provide a boiler of the desired capacity. The units l6 are mounted in the casing ID in any suitable manner, for example, each unit It may rest on a pair of angle irons 30 and may be spaced at its four corners from the next adjacent unit by spool spacers 32 carried on tie-rods or bolts which joint the several units together in a boiler assembly. The inlet conduit 22 and outlet conduit 24 are of course connected by brazing or otherwise to each of the several units I6 as will be understood.

The spacing between the units it permits the flame or the hot gases from the fire box l2 to rise vertically between the units, and the many passages provided between the plurality of units effects the maximum possible heat exchange between the flames or hot gases and the many streams of liquid being conducted through the units. A fiue header 36 is removably mounted upon suitable angle iron supports at the top of the casing Ii] in effective sealing engagement therewith and serves to collect the hot gases passing upwardly between the units It. The flue header 36 is connected removably and in sealed relation to a flue or chimney conduit 38 which extends in sealed relation through the casing Ill and into fluid tight relation with a suitable aperture in the wall W positioned between the associated casing and the main casing. The wall w often does not include insulation so that heat is transferred through the wall to further preheat entrance of air and the air flows over the flue I header 35 and down between the walls I!) and ll] to the oil burner M in the direction shown by the dotted arrows and thence into the fire box l2. In this manner, the air used in combustion is pre-heated to thereby give the best possible type of combustion action and to drain from the flue gases all of the heat except that required to give the proper non-condensing stack temperature and draft. The top of the casing In defining the passage is removably secured to the main body of the casing ID by any suitable fastening means, such as those indicated by the numbers 44, so that the entire top of the casing II] can be quickly removed whereupon the flue header 36 can be picked ofi the top of the units 16 and the units readily cleaned by brushes which are passed down between the units. It will be understood that any portions of the casing l0 subjected to heat are provided with suitable insulation 46 where the transfer of heat through the casing is undesirable. Fins 41, formed with suitable apertures for the passage of combustion air may be secured to the flue header 36, as

shown, to improve the transfer of heat from the header to the combustion air.

It is a relatively simple matter in my improved apparatus to provide an indirect water heater coil. For example, I may employ the heated water from the boiler proper to heat a house and may wish also to provide tap hot water. To achieve the desired end, and as best illustrated in Fig. 4, I provide one or more U or tromboneshaped tubes 60 which are mounted in the outlet conduit 24 and are secured to a casing 62. The tap water to be heated is circulated through the tubes 60 as will be understood.

From the foregoing, it will be recognized that the objects of my invention have been achieved by 'the provision of relatively inexpensive and highly efiicient heating apparatus adapted for substantially any installation where low pressure water or other liquids are to be heated, and adapted to the heating of residences, stores or other types of buildings. My improved apparatus is particularly characterized by the provision of relatively inexpensive, readily produced, highly eficient heat-exchange units or sections which can be assembled in any desired number to provide a boiler of the desired capacity for any iven installation. The air employed for combustion is pre-heated to an exceptional degree, my apparatus is readily adapted to the use of any known type of heat supplying means, the assembly can be readily cleaned and the deposit of fly ash and soot is largely avoided, an excellent type of heat exchange is obtained at a high efficiency, drainage is unnecessary and avoided, and the assembly is neat in appearance, low in maintenance cost and readily adapted to fulfill the requirements of any given installation.

My improved apparatus is ordinarily employed in conjunction with any of the various known temperature control thermostats and other control equipment. The heat exchange units are formed by stamping or pressing in a rapid and inexpensive manner and are welded together at low cost so that the resulting unit is relatively free from distortion or breakage due to expansion and contraction, and internal leakage is not important. I have provided a combined contraflow and parallel flow boiler wherein the fiow of the liquid is divided into a plurality of streams which are heated completely throughout their cross section and after taking a long and curved path end up flowing contiguous to the flow of the hot gases. I obtain a finer division of the burning gases than is possible with any cast iron sections or conventional steel units. The portions of each heating section lying between the tubes or passages also collect heat and pass it by conduction into the liquid carried by each unit and these portions also prohibit the accumulation of fly-ash and soot.

As a result, my improved unit or boiler assembly provides a most efiicient and inexpensive solution to any heating problem and takes up a minimum amount of space because the greatest possible amount of heat collecting surface is obtained within a given space.

While in accordance with the patent statutes, I have illustrated and described in detail one embodiment of my invention it will be understood that I am not to be limited thereto or thereby, but that the scope of my invention is defined in the appended claims.

Iclaim:

1. In combination in a boiler, a fire box, means for -supplying a flow of hot gases upwardly from the fire box, a casing positioned above the fire box, a plurality of units positioned in side by side but in spaced apart relation in the casing and extending down into the fire box so that th hot gases pass "upwardly between the units, a stack header mounted removably-on the top of the casing and adapted to carry the hot gases to a stack, a combustion-air header surrounding the stack header but spaced therefrom and removably mounted on the top of the casing, said air header being connected to and supplying combustion air for the means for supplying the hot gases, an inlet conduit connected to each unit, and an outlet conduit connected to each unit adjacent the inlet conduit, each of said units including a pair of metal plates abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a relatively long undulating passage which is substantially oval in cross section and connected at one end to the inlet conduit and terminating in, a substantially vertical passage at one edge of the unit, said vertical passage being connected to a plurality of upwardly inclined passages in turn connected to a substantially vertical passage connected to the outlet conduit, each of the uni-ts being spot welded together at a plurality of points between the passages and being seal-Welded together around its edges, and fluid stirring means in at least certain of the passages.

2. In combination in a boiler, a fire box, means for supplying a flow of hot gases upwardly from the fire box, a casing positioned above th fire box, a plurality of units positioned in side by side but spaced apart relation in the casing and extending down into the fire box so that the hot gases pass upwardly between the units, a stack header mounted removably on the top of the casing and adapted to carry the hot gases to a stack, an inlet conduit connected to each unit, and an outlet conduit connected to each unit adjacent the inlet conduit, each of said units including a pair of metal plates abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a relatively long undulating passage which is substantially oval in cross section and connected at one end to the inlet conduit and terminating in a substantially vertical passage at one edge of the unit, said Vertical passage being connected to a plurality of upwardly inclined passages in turn connected to a substantially vertical passage connected to the outlet conduit, each of the units being spot Welded together at a plurality of points between the passages and being seal-welded together around its edges.

3. In combination in a boiler, a fire box, means for supplying a flow of hot gases upwardly from the fire box, a casing positioned above the fire box, a plurality of units positioned above the fire box and in side by side but spaced apart relation in the casing so that the hot gases pass upwardly between the units, an inlet conduit connected to each unit, and an outlet conduit connected to each unit, each of said units including a pair of metal plates abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a relatively long undulating passage which is substantially oval in cross section and connected at one end to the inlet conduit and which terminates at its other end at the top of a substantially vertical passage at one edge of the unit, said vertical passage being connected to a plurality of upwardly inclined passages in turn connected to a substantially vertical passage connected at its upper end to the outlet conduit, each unit being spot welded together at a plurality of points between the passages and being sealwelded together around its edges.

4. In combination in a boiler, a fire box, means for supplying a fiow of hot gases upwardly from the fire box, a casing positioned above the fire box, a plurality of units positioned in side by side but spaced apart relation in the casing so that the hot gases pass upwardly between the units, a stack header mounted removably on the top of the casing and adapted to carry the hot gases to a stack, a combustion air header surrounding the stack header but spaced therefrom and removably mounted on the top of the casing, said air header being connected to and supplying combus tion air for the means for supplying the hot gases, an inlet conduit connected to each unit, and an outlet conduit connected to each unit, each of said units including a pair of metal plates abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a relatively long undulating passage which is substantially oval in cross section, each of the units being spot welded together at a plurality of points between the passages and being welded and sealed together around its edges.

5. In combination in a boiler, a fire box, means for supplying a flow of hot gases upwardly from the fire box, a casing positioned above the fire box, a plurality of units positioned in side by side but spaced apart relation in the casing so that the hot gases pass upwardly between the units, a stack header mounted removably on the top of the casing and adapted to carry the hot gases to a stack, a combustion-air header surrounding the stack-header but spaced therefrom and removably mounted on the top of the casing, said airheader being connected to and supplying combustion air for the means for supplying the hot gases, an inlet conduit connected to each unit, and an outlet conduit connected to each unit.

6. A heat transfer unit including a pair of metal plates abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a relatively long undulating passage which is substantially almond-shaped in cross section and adapted to be connected at one end to an inlet conduit and terminating at its other end at the top of a substantially vertical passage at one edge of the unit, the vertical passage being connected to a plurality of upwardly inclined passages in turn connected to a substantially vertical passage adapted to be connected at its upper end to an outlet conduit, the unit being spot welded together at a plurality of points between the passages and being welded and sealed together around its edges.

.7. A heat transfer unit including a pair of metal plates abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a relatively long undulating passage, an in let conduit connected at one end of the passage, said passage terminating at its other end at the top of a substantially vertical passage at one edge of the unit, the vertical passage being connected to a plurality of upwardly inclined passages in turn connected to a substantially vertical passage, an outlet conduit connected to the upper end of the last-named vertical passage and at a point adjacent the inlet conduit, the unit being spot welded together at a plurality of points between the passages and being welded and sealed together around its edges.

8. A heat transfer unit including a pair of metal plates abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a relatively long undulating passage and adapted to be connected at one end to an inlet conduit and terminating at its other end at the top of a substantially vertical passage at one edge of the unit, the vertical passage being connected to a plurality of upwardly inclined passages in turn connected to a second substantially vertical passage adapted to be connected at its top to an outlet conduit.

9. In combination in a boiler, a fire box, means for supplying a flow of hot gases upwardly from the fire box, a casing positioned above the fire box, a plurality of units positioned in side by side but spaced apart relation in the casing so that the hot gases pass upwardly between the units, an inlet conduit connected to each unit, an outlet conduit connected to each unit, each of said units including a pair of metal plates abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a relatively long undulating passage connected at opposite ends to the inlet and outlet conduits, and flow interrupting baffles in the passage.

10. A heat transfer unit including a pair of metal plates abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a relatively long undulating passage and adapted to be connected at one end to an inlet conduit and terminating in a substantially vertical passage at one edge of the unit, the vertical passage being connected to a plurality of upwardly inclined passages in turn connected to a substantially vertical passage adapted to be connected to an outlet conduit, the unit being spot welded together at a plurality of points between the passages and being welded and sealed together around its edges, and flow interrupting baffies in at least certain of the passages.

11. A heat transfer unit including a pair of metal plates abutting face to face with the plates being pressed outwardly in juxtaposed areas to form a relatively long circuitous passage adapted to be connected at one end to an inlet conduit and at the other to an outlet conduit, the passage being arranged to be in part a contra-flow so far as heating gases are concerned, the unit being spot welded together adjacent the passage and welded and sealed together around its edges, and flow interrupting baffles extending into the passage, said baffies being integral with the plates and being pressed therein when the passage is pressed.

12. In combination in a boiler, a fire box, means for supplying a flow of hot gases upwardly from the fire box, an air intake on said means, a casing positioned above the fire box, a plurality of heat exchange units positioned in side by side but spaced apart relation in the casing so that the hot gases pass upwardly between the units, a stack header mounted on the top of the casing and adapted to carry the hot gases to a stack, a combustion air header surrounding the stack header but spaced therefrom and mounted on top of the casing, means connecting the air header to the air intake of the means for supplying hot gases, an inlet conduit connected to each unit, and an outlet conduit connected to each unit.

13. In combination in a boiler, a fire box, means for supplying a flow of hot gases upwardly from the fire box, a casing positioned above the fire box, a plurality of heat exchange units positioned above the fire box in side by side but spaced apart relation in the casing so that the hot gases pass upwardly between the units, an inlet conduit connected to each unit adjacent the top thereof, means defining a relatively long passage in each unit adapted to receive liquid from the inlet conduit, said passage extending substantially horizontally substantially the width of the unit then down a short distance then back substantially horizontally substantially the width of the unit, then down a short distance, then back substantially horizontally substantially the width of the unit, the passage then extending in a substantially vertical direction along one edge of the unit, the vertical passage being connected to a plurality of upwardly inclined passages opening into a substantially vertical passage along the other edge of the unit, and an outlet conduit connected to the upper end of the lastnamed substantially vertical passage in each unit.

14. A heat exchange unit including a pair of plates secured together around their edges, an inlet conduit connected to each unit adjacent the top thereof, the unit having a relatively long passage adapted to receive liquid from the inlet conduit, said passage extending substantially horizontally substantially the width of the unit then down a short distance, then back substantially horizontally substantially the width of the unit, then down a short distance, then back substantially horizontally substantially the width of the unit, the passage then extending in a substantially vertical direction along one edge of the unit, the vertical passage being connected to a plurality of upwardly inclined passages opening into a substantially vertical passage along the other edge of the unit, and an outlet conduit connected to the upper end of the last-named substantially vertical passage.

STEWART P. FOLTZ. 

